A cooking unit includes a cooktop, a hood assembly, a duct assembly, and a fan. The cooktop defines a slot at least partially extending along a peripheral edge of the cooktop. The hood assembly includes a hood support extending upward from the cooktop and a hood coupled to the hood support. The hood support defines a conduit. The hood defines an intake and a hood chamber connecting the intake to the conduit of the hood support. The duct assembly includes ducting extending beneath the cooktop. The ducting connects the conduit to the slot. The fan is positioned to drive air into the intake, through the hood chamber, through the conduit, through the ducting, and out of the slot. At least a portion of the air exiting the slot returns to the intake such that an air curtain is generated between the slot and the intake.